(a) Field of the Invention
The present invention relates to a method and system for measuring an initial hydrocarbon concentration in a canister, and for controlling vehicle fuel injection.
(b) Description of the Related Art
The automotive industry has actively sought to reduce pollutants in exhaust gases. One method for reducing pollutants in exhaust gases is by using canister purge.
Generally, gasoline in a fuel tank includes a mixture of hydrocarbons ranging from higher volatility butanes (C4) to lower volatility C8 to C10 hydrocarbons. When the temperature of the surroundings is high or vapor pressure in the fuel tank is increased by movement of the gasoline, fuel vapor leaks through crevices in the fuel tank. To prevent this leakage, the fuel vapor is vented into a canister.
The canister has absorbent material for absorbing the fuel vapor. If the hydrocarbons HC absorbed by the canister were vented into the atmosphere, the engine would not meet exhaust gas regulations. Therefore, an engine control unit operates a purge control solenoid valve in order to vent the hydrocarbons from the canister into the engine. In order to precisely control air and fuel amounts supplied to the engine, it is very important to measure the hydrocarbon concentration in the canister.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.